Retractable continuous drive



Feb. 5, 1963 E. SHIPLEY 3,076,428

RETRACTABLE CONTINUOUS DRIVE Filed Sept. 25, 1961 (D #2 a g;

o I 8 F a a i n v N 5 IE I INVENTORI EUGENE E.SH|PLEY.

BY wim HIS ATTORNEY.

United States Patent f 3,076,428 RETRACTABLE CiJNTltNUOUS DRIVE EugeneE. Shipley, Middleton, Mass, assignor to General Electric Company, acorporation of New Yorlr Filed Sept. 25, 1961, Ser. No. 140,308 Claims.(Cl. 115-41) This invention relates to a retractable continuous drivemechanism, and more particularly to a retractable continuous drivemechanism which is particularly suitable for a propeller driven boat orthe like.

Hydrofoil boats may generally be operated in two positions, either up onstruts attached to water foils or on the hull like a conventional boat.t is desirable that such a boat be provided with an auxiliary powerdrive mechanism which will propel the craft either when it is supportedby the foils or by the hull. Frequently, separate drive mechanisms havebeen employed for hydrofoil or hull operation. The present inventionprovides a retractable drive mechanism or propeller assembly which canbe easily moved to remain at the same depth in the water while the boathull is at different vertical levels, such as either on its foils or onits hull surface.

Accordingly, it is the primary object of the invention to provide animproved retractable propeller drive mechanism.

It is a further object of the invention to provide a retractablecontinuous drive mechanism that may be retracted while driving, withoutinterruption of continuous power. Another object of the invention is toprovide a retractable propeller assembly for boats or the like which maybe continuously driven while the propeller is being raised or lowered tobe operated in various positions.

Briefly stated, the invention relates to a retractable drive mechanismcomprising an engine-driven vertical spline shaft and a verticallyretractable propeller as sembly positioned in parallel relationship tothe spline shaft. Power transmission means is slidably mounted on thespline shaft and carried by the propeller assembly to drive thepropeller. In addition, servo means is provided to move the propellerassembly vertically in a direction parallel to the spline shaft.

Further objects, features and advantages of the invention will becomeapparent from the following specification and drawing in which the soleFIGURE is a sectional view of a retractable continuous drive mechanismincorporating the invention.

The retractable continuous drive mechanism of the invention ispositioned ina housing 11, which may be firmly attached to the hull of ahydrofoil type boat which is partially shown at 12. A driving input fromthe engine (not shown) may be introduced to the retractable drivingmechanism by means of a shaft 13 extending through a side wall of thehousing 11. A spline shaft 14 is rotatably mounted in a vertically fixedposition within the walls of the housing 11 by means of bearings 15 and16 and is driven by input shaft 13 through bevel gears 17 and 18.

A propeller assembly shown generally at 20 is supported by the lowerwall 21 of the casing 11. The propeller assembly 20 comprises a hollowstrut 22 slidably mounted to extend vertically and parallel to splineshaft lidthrough the casing wall 21. The strut 22'supports a telescopicoutput shaft 23, a propeller pod 24, a propeller shaft 25, a propeller26, and suitable means for transmitting torque to and from the shaft 23.

In the present embodiment, torque is transmitted to the output shaft 23from the spline shaft 14 by a pair of spur gears 27 and 28. A gear box29, attached to the upper end of hollow strut 22, houses the spur gears27 and 28.

In accordance with the invention, spur 27 is slidably 3,676,428 PatentedFeb. 5, i983 ice mounted on the spline shaft 14 and engages and drivesspur gear 28, which is securely attached to output shaft 23. Gear box 29is provided with an opening 3d through which spline shaft 14 passes, sothat spur gear 27 is carried by gear box 29 as the propeller assembly 29is moved up or down as will be hereinafter explained.

Describing the propeller assembly Ell in more detail, it can be seen bythe drawing that the output shaft 23 is formed of a hollow cylinder 31slidably positioned around a vertical piston member 32. The lower end 33of the piston member 32 is formed to fit snugly within the hollowportion 29. The piston member 32 is rotatably mounted by suitablebearings 34 in the top wall of casing 11, and the hollow cylinder 31 isrotatably mounted in bearings 35 supported by propeller pod 2d. Thehollow cylinder 31 carries torque from spur gear 28 to a bevel gear 36on its lower end. An additional bevel gear 37 cooperates with bevel gear36 to drive propeller shaft 25 and propeller 26.

It will be appreciated that with the mechanism as heretofore described,the propeller assembly 26 carrying spur gear 27 is not firmly attachedto spline shaft 14 and may be moved in a direction parallel to thespline shaft, if means for moving the propeller assembly 20 areprovided, such as a servo arrangement. One means to accomplish this isto utilize the hollow cylinder 31 and piston member 32 of shaft 23 as ahydraulic cylinder and piston arrangement. To move the cylinder 31 ofoutput shaft 23 either downwardly or upwardly, hydraulic fluid may beadmitted to either side of the piston head 33. One means ofaccomplishing this is through the use of a pipe 43 connected to supplyhydraulic fluid through a central conduit 32a in piston 32 to a lowerchamber 38 below piston head 33. Fluid is supplied to a chamber 46 onthe top side of piston head 33 through a sealed annulus id and aflexible hose 55. introducing hydraulic fluid into the lower chamber 38,defined by cylinder 31 and piston head 33, will cause the hollow shaftportion and thus the entire propeller assembly 26 to move downwardly.Alternately, applying fluid to chamber is will cause the cylinder 31 andthe propeller assembly 20 to retract or move upwardly. As the propellerassembly 20 is moved, gear box 29 also moves. Thus the spur gear 27slides on spline shaft 1 Gear 27, of course, remains engaged with spurgear 23 securely attached to cylinder 31 of shaft 23. Cylinder 31 thuscontinuously transmits torque to propeller 26.

It should be noted that although spur gear 28 is attached to the torquetransmitting cylinder 31 of shaft 23, the piston member 32 of the shaftrotates with the cylinder, since the upper end piston 32 is mounted onbearings 34. The friction between the contacting surfaces of the twoshaft portions is sufficient to cause the piston 32 to rotate with thecylinder 31.

Since the retractable strut 22 passes through the lower wall 21 of thehousing extending into the water, suitable seals 39 and 4i) may beprovided adjacent the strut bearings 4i and 42 to prevent leakage intoor out of the casing 11.

Thus, it will be appreciated that a retractable continuous drivemechanism has been described by which propeller 24 may be continuouslydriven while it is being moved upwardly or downwardly by the hydraulicservomechanism. The propeller assembly 20 may be conveniently andquickly moved into an extended position whereby it may be used to drivethe boat 12 when it is supported by the hydrofoils, or the assembly maybe retracted to the position shown in the drawing to drive the boat whenit is supported by its hull.

To relieve the continuous duty of the servo mechanism if the boat is tobe operated for any extended period of time in the retracted positionorthe extended position,

a locking device (not shown) could be provided to hold the retractableassembly 20 fixed relative to the housing 11. In this manner, thecontinuous retractable drive would be converted into a stationary driveand the servo mechanism could be shut off until the retractable featurewas required again.

The retractable drive mechanism has been shown and described as a powersource for a hydrofoil type boat. However, it should be appreciated thatthe mechanism may be utilized in any application wherein a retractabledrive arrangement is desired. It should further be appreciated thatwhile the mechanism has been shown and described in a vertical position,it may, of course, be operated in different attitudes in that it is onlyessential that the retractable assembly 20 be moved in a paralleldirection with respect to spline shaft 14. It should be understood thatthe particular propeller pod and bevel gear arrangement here describedis merely exemplary and that a variety of arrangements may be employedinvolving more or less complexity. Also, as mentioned before, a varietyof servo means may be provided to move the propeller assembly in adirection parallel to spline shaft 11, and the invention is not limitedto the hydraulic arrangement shown.

Therefore, it will be appreciated that the particular embodimentsdescribed are primarily examples of the invention, and it will beobvious to those skilled in the art that many changes and modificationsmay be made without departing from the invention in its broader aspects.

Having thus described the invention, what is claimed is:

l. A retractable continuous drive mechanism comprising:

(a) a housing,

(I?) a driven spline power shaft rotatably mounted within said housing,

() a retractable propeller assembly including:

(1) a propeller shaft,

(2) a propeller mounted on said propeller shaft and,

(3) an output shaft coupled to said propeller shaft for driving saidpropeller, said output shaft being parallel to, displaced from, anddriven by said spline power shaft,

(d) power transmission means slidably mounted on said spline power shaftand carried by said propeller assembly to drive said assembly, and

(e) servo means to slide said propeller assembly through said housingwall in a direction parallel to said spline shaft.

2. The mechanism of claim 1 in which said transmission means comprises adriving gear slidably mounted on said spline shaft and a driven gearfixed to said output shaft.

3. A retractable continuous drive mechanism comprising:

(a) a housing,

(b) a driven spline shaft rotatably mounted within said housing,

(c) a retractable propeller assembly comprising:

(1) a telescopic output shaft parallel to, displaced from and driven bysaid spline shaft,

(2) a hollow strut surrounding and rotatably supporting said outputshaft and slidably extending through a wall of said housing and,

(3) a propeller coupled to be driven by said output shaft,

(d) power transmission means slidably mounted on said spline shaft andcarried by said propeller assembly to drive the assembly and,

(e) servo means to slide said propellerassembly through said housingwall in a direction parallel to said spline shaft.

4. The mechanism of claim 3 in which said servo means comprises saidoutput shaft having a hollow cylindrical portion rotatably mounted insaid housing and a piston portion slidably mounted inside saidcylindrical portion and dividing said cylindrical portion into separatechambers, and said servo means including means to selectively introducefluid to said chambers to thereby slide said strut through said housingin a direction parallel to said spline shaft.

5. The mechanism of claim 3 in which said output shaft has a firstportion one end of which is rotatably mounted in said housing and theopposite end of which is enlarged to form a piston, and said outputshaft has a hollow second portion slidably mounted around said piston tothus form a chamber on each side of said piston, said hollow strutsurrounding and rotatably supporting said second portion of said outputshaft and slidably extending through a wall of said housing, and inwhich said servo means includes means to selectively introduce hydraulicfluid to said chambers to thereby slide said strut through said housingin a direction parallel to said spline shaft.

6. The mechanism of claim 3 in which said output shaft has a firstportion one end of which is rotatably mounted in said housing and theopposite end of which is enlarged to form a piston, and said outputshaft has a hollow second portion slidably mounted around said piston tothus form a chamber on each side of said piston, said hollow strutsurrounding and rotatably supporting said second portion of said outputshaft and slidably extending through a wall of said housing, and inwhich said servo means includes means to selectively introduce hy--draulic fluid to said chambers to thereby slide said strut thorugh saidhousing wall in a direction parallel to said spline shaft, and in whichsaid transmission means comprises a driving gear slidably mounted onsaid spline shaft and a driven gear fixed to said second portion of saidoutput shaft.

7. The mechanism of claim 3 in which said output shaft is axiallymovable.

8. The mechanism of claim 7 in which a pod is mounted on one end of saidstrut supporting said propeller and a propeller shaft driven by saidoutput shaft.

9. The mechanism of claim 7 in which said transmission means comprises adriving gear slidably mounted on said spline shaft and a driven gearfixed to said output shaft.

10. In a power transmission for continuously driving a retractablepropeller assembly, the combination of a housing, a first verticalspline shaft rotatably disposed in said housing, a power means forcontinuously rotating said spline shaft, a retractable propeller podassembly having a hollow supporting strut slidably disposed through atom wall portion of said housing for movement vertically and parallel tothe axis of said spline shaft, a propeller rotatably disposed in saidpod assembly, an output shaft parallel to and displaced from said splineshaft and rotatably disposed in said strut, said output shaft connectedto drive said propeller, gear means connecting said output shaft to becontinuously driven by said first shaft and comprising a gear housingconnected to the upper end portion of said slidable strut and containinga first gear fixed to said output shaft and driven by a second gearslidably disposed on said first spline shaft to be contin' uously driventhereby, and servo means for causing said strut to slide vertically inthe housing while the output shaft is continuously driven by said gearmeans.

References Cited in the file of this patent UNITED STATES PATENTS1,124,645 Overton Jan. 12, 1915 1,823,735 Glasby Sept. 15, 19312,479,119 Johnson Aug. 16, 1949 2,984,197 Bader May 16, 1961 FOREIGNPATENTS 526,415 Italy May 17, 1955 793,410 Great Britain Apr. 16, 958.

1. A RETRACTABLE CONTINUOUS DRIVE MECHANISM COMPRISING: (A) A HOUSING,(B) A DRIVEN SPLINE POWER SHAFT ROTATABLY MOUNTED WITHIN SAID HOUSING,(C) A RETRACTABLE PROPELLER ASSEMBLY INCLUDING: (1) A PROPELLER SHAFT,(2) A PROPELLER MOUNTED ON SAID PROPELLER SHAFT AND, (3) AN OUTPUT SHAFTCOUPLED TO SAID PROPELLER SHAFT FOR DRIVING SAID PROPELLER, SAID OUTPUTSHAFT BEING PARALLEL TO, DISPLACED FROM, AND DRIVEN BY SAID SPLINE POWERSHAFT,